Rust preventive composition



2,893,880 I RUST COMPOSITION Edgar A. Dieman, Crown Point, Ind., and'Alf T. Swanso'n', Chicago Heights, 111., assignors to Standard Oil Company, Chicago, 11]., a corporation of Indiana No Drawing. Application October 30,1956 Serial No. 619,130 1 6 Claims. Cl. 106-44) This invention relates toimprovements in corrosion inhibiting compositions otherwise known as sloshing compounds, and more particularly is directed to dry film type corrosion inhibiting compositions for protecting metal surfaces, particularly those of ferrous and related metal or alloy products from rusting and from the corrosive action of air or oxygen in the presence of moisture or other aqueous liquids. I I

Metal surfaces whenever possible are protected from corrosion and/or rusting by a coating of some kind. In general, two types of protective coatings have been em ployed, namely permanent and temporary coatings. the first class are included oxide coatings, phosphate coatings, paints, varnishes and other non-metallic materials which form dry, hard films. In the second class of protective coatings which are of the type which must at some time be readily removed from the surfaces they are protecting are those products prepared from oleaginous materials, such as petroleum oils, petrolatums, waxes, greases, asphalts, etc. While such products give satisfactory protection under certain conditions, under many conditions they do not provide the protection desired, and require the addition thereto of rust and/ or corrosion inhibitors. Anti-rust or slushing compositions are used for the protection of metals either in the form of stock or fabricated articles against corrosion and/or rusting. Materials prior to storage should be coated with an anti- 2,893,880 Patented July '7, 1959 In place of the above sperm wax or in combination;

therewith, the hydrogenated sperm wax can be used,

'Ihe hydrogenated sperm mate analysis:

Iodine No. '7 .0 max.

wax has the following-approxi- Saponification No. 125-135;: Acid'value 4 max. I I Unsaponifiables l. 40-50%. Melting point 115-125 F. Flash point; 485 F."

'Ilhe surfactant compound is preferably an alkaline earth sulfonate, preferably calcium mahogany soap, i.e.

the calcium soap of a preferentially oil-soluble petroleum coheptitol, nonitols, talitol, etc. Such polyhydric alcohols undergo intramolecular dehydration to form the anhydro-.

alkitols, which are polyhydric cyclic ethersL The esters are readily obtained'by esterifying anhydroalkitols by conventional esterification procedures with a variety of acids such as fatty acids, aliphatic carboxylic acids con- ,taining a branched-chain structure and/or an odd number of carbon atoms. For the present invention, it is preferred to use the esters of anhydroalkitols and fatty acids having :8 to about 30 carbon atoms, per molecule such as for example, caproic, capric, iauric, palmi-tic, oleic, stearic,

oleostearic, linoleic, dehydroxystearic, erucic and behenic acids. Examples of preferred esters are sorbitan' monolaureate, sorbitan mono-oleate.

The preferentially oil-soluble mahogany soaps of the alkaline earth metals are produced by treating petroleum distillates of between about 50 and 1000 seconds or higher Saybolt Universal viscosity at 100 F. and pref- I erably between about 80 and 300 seconds SSU at 100 F. with between about 3 and 9 pounds, and preferably between about 3 and 6 pounds of concentrated sulfuric acid,

rust material to prevent corrosion and/or rusting while in storage; and finished or semi-finished metal stocks destined for shipmentby rail or by water must be proteoted against attack by'moisture by cOatin-gsuch ma'- terials with suitable anti rust or slushing compounds. Materials for shipment overseas must be protected against attack by salt spray.

It is an object of the present invention to provide dry film type anti-rust compositions which will eifectively prevent and/or inhibit corrosion of metal'surfaces. Another object of the present invention is to provide improved slushing and/0r anti-rust compositions of the dry film type.

In accordance withthe present invention, the foregoing objects can be attained by employing slushing compositions comprising essentially from about 2% to about 30% sperm wax or hydrogenated sperm'wax or mixtures thereof and from about 0.5% to about 10% of a surfactant compound, and from about 60% to about 97.5% of a normally liquid hydrocarbon diluent.

The sperm wax component is preferably a product obtained by crystallization at about F. of the crude sperm oil, to obtain a sperm wax having the following preferably fuming sulfuric acid, per gallon of oil. The calcium soaps of preferentially oil-soluble mahogany acids are preferred, and the preparation thereof is illustrated I by the following example. i I

A Mid-Continent petroleum distillate having a Saybolt Universal viscosity at 100 F. of between about 220-230 seconds is treated with 6 pounds of fuming sulphuric acid per gallon of oil in one-half pound dumps. separation of the acid sludge, the acid-treated oil is treated with a'suitable alcohol, for example, ethanol, of about 60% strength, to remove crude petroleum sulphonic acid.

The alcoholic layer containing the crude sulphonic acid is then treated with lime slurry to neutralize the petroleum sulphonic acid. The mixture is allowed to settle, the alcoholic layer containing the calcium mahogany soapis drawn ofi, and then passed to a distillation column where-" in the alcoholis'recove'red. The resultant calcium mar-f. hogany soap is usually a--80% concentration in unreacted oil. To facilitate handling of the soap, it is preferred to further dilute the soap with a parafiinic oil having a viscosity of between about and seconds, SSU at F. to a concentration of about 37%. The molecular weight of the sulfonate soap may lie in the range of 410 to 450 or about 430.

The normally liquid hydrocarbon diluent or solvent is suitably any aliphatic or aromatic hydrocarbon having; a distillation range of from about F. to about 450-500 F., for example, naphthas, kerosene, gas oil, benzene, toluene, xylenes, etc. A preferred diluent is a petroleum naphtha having an initial boiling point of about 300 F. and an end point of about 400 F., such-r After the in inhibiting corrosion is demonstrated by .therdata in- Table :I. These data were obtained by subjecting sand blasted steel:testpanels coated with the varioustcompositions to the humidity cabinet test and the time before rusting occurs notedin -each instance.

'In the humidity test the steel panels are suspended in a special cabinet described in the National "Military Estab-' lishment specification designated JANH'792('6-21-49 and the time of initial corrosion of the panels .noted. The humidity'cabinetjis providedwith heating units and thermal regulatorsfor automatictemperature control at 120 F. (12 F.). A water level is maintained inthe bottom of the cabinet to give approximately 100% humidityat all times. The steel panels are c'oatediby dipping "intotherust preventive material and are suspended in the cabinet by stainless steel or .Monel hooks.

- 4 (Sample 4) or the samples with the sorbitan fatty acid ester without the sperm wax (Samples 5, and 11) gave protection of only 19 to 60 hours.

Percentages given herein and in the appended claims are weight percentages unless otherwise stated.

We claim:

1. A rust preventive composition consisting essentially of from about 2% to about 30% of a normal wax selected from the class consisting of sperm wax, .hydrogenated sperm wax and mixtures thereof, from about 0.5% .to about 10% of a surfactant selected from the class consisting of an alkaline earth soap of a preferentially oil-soluble petroleum 'sulfonic acid'and a-fatty acid ester of an anhydroalkitol, and from about 60% to about 97.5% of a'hydrocarbon normallyliquid diluent.

2. A composition as described in claim 1 in which the alkaline earth soap of a preferentially oil-soluble petroleum sulfonic acid is calcium mahoganysoap.

3. A composition as described in claim 1 in whichlthe fatty acid ester of ananhydroalkitol is amono-fatty acid ester of sorbitol.

4. A composition as described in claim 1 in which the fatty acid ester of an anhydroalkitol is sorbitan monooleate.

5. A rust preventive composition-consisting essentially of from about 2% to about of asperm wax, from about-0.5% .to about 1.0% of .a calcium mahoganysoap,

Table 1 Sample No.

l a a 4 5 2 6 7 s 9 10 11 I 12 13 1 14 Composition, percent: i .Hydrogenated Sperm Wax l 5 .5 5 0: 0 -5 5 l0 .5 5 0: 0' 10 .10 -Sperm Wax 0 5 0' 0 0 .0 0 0 5 5 O 10 O 0 Solvent 95 '90 .90 '95 95 '90 90 85 87 07 87' 85 80 Calcium Mahogany 8021 c 0- 0 -0 5 0 5 0 0: 5 0 0 0. 0' '5 'Mono-fatty acid ester of sorbitol 3 0 0 '0 0 p 5 0 5 5 0 -3 3 3 0, 0 Hydrocarbon Oil 4 0 0 "5' 0 0 0 0 0 0 0 0 '5 5 Protection in Hours 16-. '16- 16- 19-, .60 570+ 600+ 600+ 520+ 520+ 19- 520+ 16 520+ l Marketed as Moby Dick Hi Wax 120'by Werner G. Smithflnc.

2 Marketed Wax by Werner 'G. Smith, Inc. Marketed as Atpet by Atlas Powder Company.

| Paratfin distillate oil Saybolt Universal viscosity at 100 F. of 80 sec ends.

The synergistic elfectof thecombination of thesperm absence of the surfactant gave protection of only 16 hours, the combination of the sperm .wax, hydrogenated sperm wax or combinations thereof with calcium mahoganysoap (Samples 4, 9, and 14) or .with the :sorbitan 2,430,846

monoffatty acid ester (Samples 7, 8, .10,-and 12;) gave protection of 520+ to 600+ hours. The samples Wlilll the calcium mahogany soap without the sperm wax and from about 60% to about 97.5% of-a hydrocarbon diluenthaving a distillation range of from about -F. to about 500 F.

.6. A rust preventive composition consisting essentially of from about 2% to about 30% of a sperm wax, from about 0.5% to about 10% of a mono-fatty acid ester of -sorbitol,and from about 60% to about 97.5 %of ahydrocarbon diluent having a distillation range-of from about 150 F. .to about 500 -F.

References Cited in the file of this patent UNITED STATES PATENTS Morgan Nov. 11, .1947 2,611,711 Costello Sept. 23,-1952 2,716,611 Paxton Aug. 30, 1955 2,791,510 Sproule et a1 May 7, 1957 

1. A RUST PREVENTIVE COMPOSITION CONSISTING ESSENTIALLY OF FROM ABOUT 2% TO ABOUT 300% OF A NORMAL WAX SELECTED FROM THE CLASS CONSISTING OF SPERM WAX, HYDROGENATED SPERM WAX AND MIXTURES THEREOF, FROM ABOUT 0.5% TO ABOUT 10% OF A SURFACTANT SELECTED FROM THE CLASS CONSISTING OF AN ALKALINE EARTH SOAP OF A PREFERENTIALLY OIL-SOLUBLE PETROLEUM SULFONIC ACID AND A FATTY ACID ESTER OF AN ANHYDROALKITOL, AND FROM ABOUT 60% TO ABOUT 97.5% OF A HYDROCARBON NORMALLY LIQUID DILUENT. 